Flood Taskforce
Flood risk in Sumner and Moncks Bay
Christchurch City Council footer text
Outline
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Flood Taskforce purpose
Storm events
Vulnerability levels
Areas assessed
Temporary flood defence
toolbox
6. Next steps
7. Questions
Eastern Terrace - April 2014
Squire Street - June 2013
Flood Taskforce purpose
“ Assisting the most vulnerable homes to
cope with the frequent flooding caused by
the earthquakes”.
Slater Street – June 2013
Which areas were covered by the Flood Taskforce?
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Lower Avon River
Dudley Creek (including Flockton)
Lower Heathcote (including Woolston/Opawa)
Upper Heathcote
Heathcote Valley
Southshore
Sumner (including Redcliffs)
Little River
Lyttelton
Storm events since 1961
Vulnerability Levels
• Three vulnerability Levels for multiple
flooding occurrences since the earthquakes
Findings
Identified number of households
Vulnerability Level since the earthquakes
1
2
3
(multiple
(multiple
(access cut
Areas
floods in floods under from the home
investigated
the home) the home)
repeatedly)
by Taskforce
Sumner Village
1
0
0
Moncks Bay
0
0
0
* Properties identified in the May 2014 Taskforce Report by Customer Service Requests; flood
modelling confirmed by visual inspections.
Note: 7 properties recorded as flooded above floor level once
since earthquakes
Flood Defence Toolbox
Local Area Schemes for Wakefield / Paisley Area
Christchurch City Council
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Wakefield Ave / Paisley St Area
Christchurch City Council
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Wakefield Ave / Paisley St Scheme
Phase 1 Recommendations
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Removal of sediment from Sumner Stream
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Increase inlet and pipe capacity of sumps outside 125
Wakefield Ave
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Liaise with CERA to mitigate both short and long term
sediment and runoff issues from Red Zone
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Van Asch St bridge being replaced by SCIRT
Christchurch City Council
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Mariner Street Area
Cave Rock
Drain Outfall
Cave Rock
Outfall
Burgess Street
Outfall
Christchurch City Council
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Richmond Hill Drain / Mariner St Area
Phase 1 Recommendations
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Investigate options for improved outfalls at Cave Rock and
Burgess St to to mitigate operational issues related to sand
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Formalisation of the secondary flow path from Cave Rock Drain
outfall (surf club)
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Prepare specific operational and emergency response plan to
document critical requirements for operation of the system
Christchurch City Council
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Other Recommendations
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Undertake immediate maintenance on SFRP flap gate to
ensure fully operational
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Investigate options for providing ability to manually open SFRP
flap gate
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Reinstate bolts on SFRP manholes
Christchurch City Council
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Other Recommendations
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Assess sediment levels and programme removal sediment and
other constrictions from Sumner Main Drain between Truro and
Colenso streets
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Monitor sediment levels in SFRP once flap gate operational and
programme cleaning if required
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Cleaning out road side swale on Heberden Ave / Arnold St
intersection to reduce runoff across road, possible footpath
improvements same area to minimise runoff into private
property (36a Heberden Ave)
Christchurch City Council
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Next steps
Flood Taskforce
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Ongoing maintenance activities
Further investigations for solutions
Flooding recommendations delivered to Council and government
Residents
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Complete a survey
On-going contact
One-on-one meetings with engineers if a solution affects your
property
Christchurch City Council
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Questions?
Call Centre: 03 941 8999
Website: www.ccc.govt.nz
Email: floodmitigation@ccc.govt.nz